Masking Fluid Flow Extender for Watercolor Painting, Sue's Solution, 16 Ounces Dip your brush in this before using masking fluid, and the masking fluid will go on like a dream! Allows you to paint with masking fluid much longer before the brush gets clogged up Not harmful to brushes; can even use with good sable brushes Stir in a small amount to your bottle of masking fluid and it will extend the life of your masking fluid much longer Comes in 8 ounce bottle with full set of instructions and ships within 24 hours from ARThouse; you will wonder how you lived without this!